Die-blank.



P. E. WELLS.

DIE BLANK.

APPLIOATION FILED FEB. 19, 1912.

1,048,921. Patented Dec.31 ,1912.

WITNESSES: JNVENTOR,

ATTORNEY.

FREDERIC E. WELLS, OF GREENFIELD, MASSACHUSETTS.-

DIE-BLANK.

Specification of Letters Patent.

Patented Dec. 31,1912.

Application filed February 19, 1912. Serial No. 678,616.

To all whom it may concern:

Be it known that I, Fnnonnio E. WELLS, a citizen of the United States ofAmerica, residing at Greenfield, in the county of Franklin and State ofMassachusetts, have invented new and useful Improvements in Die-Blanks,of which the following is a specification.

This invention relates to improvements in thread-cutting dies, and moreparticularly to the method of forming the finished blank prior to theformation of the threads of the die.

The invention, in its completed form, comprises a ribbed blank memberand a thin, or somewhat reduced rim portion with a slit in the edgethereof to permit the rim to yield or spring, if desired, for cuttingthreads of different diameters.

Blanks from which dies are made are usually composed of a solid piece ofsteel requiring the removal of the surplus material by drilling orboring, which operation is an expensive process consuming not only agreat deal of time, besides the waste of expensive material. Applicantsblank is formed from a solid piece of steel which is subjected to thedrop forging process leaving the finished blank in shape for finishingthe die; that is to say, for forming the cuttingteeth, and the otheroperations or processes for completing the die.

In the drawings forming part of this application,-Figure l is an edgeview of the stock from which the finished block is to be forged. Fig. 2shows a transverse sectional view on the line 22 of Fig. 3. Fig. 3 is aplan view of Fig. 2 showing the diametri cally arranged ribs joined atthe center, and rim portion of the blank. Fig. 4 is a plan view of thefinished die showing the slit in the rim portion, the adjusting screw,and the cut-ting teeth.

Referring to the drawings in detail, a designates a block of the stockfrom which the die is to be formed by the drop forging process. Figs. 2and 8 show the blank after it has been subjected to this process inwhich the ribs 7) are struck up, being formed integral with each otherat the center of the blank and the rim 0 at their outer ends. The webs(Z between the ribs are also integral with the ribs and rim, and inplanes at substantially right angles to each other. The webs also serveto completely close one side of the finished blank and the rim, webs andribs form separate pocket spaces. The metal of the original stock-piecea, as shown in Fig. 1, has therefore been forged into the blank shown inFigs. 2 and 8. The next step in the process of making the finished dieis to punch out the portions of metal from the webs (Z of the blank,shown in Fig. 3, and as indicated in Fig. 4: by the openings 6, f, and9, thus forming the four inwardly projecting ends it on which thecutting teeth are formed; or, the center portion a may be first removedby drilling, and the openings 6, f, and 9 then formed. A slit 7' is cutin the rim 0 so as to permit the adjusting screw 70 to vary the size ofthe thread to be cut. This screw is placed in a threaded opening at andextends across the slit 7' and engages the curved cornered portion 1' ofthe ribbed blank.

This particular invention relates to the formation of the cupped-shapedblank construction shown in Fig. 3, in contradistinction to the solidmetal blank heretofore in use.

WVhile the drawings and description show and describe a circular shapedadjustable die, the invention is also applicable to dies of any desiredshape.

that I claim, is

l. A die-blank of general cup-shaped construction, ribs extendingtransversely of the blank, and integral webs between the ribs,

and the outer portions of the blank and in a plane at right angles tothey ribs.

2. A die blank formed from a solid disk or blank and comprising a rimportion, the diameter of which is equal to the diameter of the soliddisk, a web-portion integral with the rim portion and at right anglesthereto, rib-members connected together at the cen ter portion of theblank and equal to the thickness of the finished rim portion, the

web-portion completely closing one side of and web portions formingindependent the finished die-blank, as described. pocket spaces.

8. In a ribbed die-blank, a rim formed integral with the ribbed portionand webs 5 integral with the rim and ribs, said ribs Witnesses:

being integral with each other at their cen- OLIVE M. LONG, terportions, the space between the rim, ribs, ARCHIBALD D. FLOWER.

FREDERIC E. WELLS.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

7 Washington, D. C.

